A tool cabinet is mainly used for uniform management of materials in all trades. The main structure of the conventional tool cabinet is typically one whole body, which is heavy and not easy to carry. There are complicated structures, such as mosaic assembly type, screw lock type etc, but it is disadvantageous in using tool to disconnect and assemble them. For the assembled tool cabinet of large volume, which is not fit for carrying as a whole, once carrying, it is necessary to disconnect by the aid of tools at first, then reassemble it by tools to the destination. It is fussy and time-consuming. On the other hand, when the tool cabinet is free of use, it will still take much space. Hence, it becomes a new task of design for the current tool cabinet to improve variability of its combined structure and its compatibility with the space.